The present invention pertains to variable electrical resistance means and, in particular, to a signal controlled potentiometer.
Variable restance means, such as potentiometers, are well known in the electronics art. Commonly, such potentiometers are fabricated by arranging a movable tap to be located at adjustable positions between the end points of a resistive element. A voltage applied across the resistive element may be divided by a given value as determined by the
In many applications, such as the remote control art, the user may wish to vary the tap position of a potentiometer which is within equipment remotely located from the user. For example, in the communication art it is not uncommon for a user to vary the tuning of a remotely located receiver or transmitter by sending a coded tone over the telephone lines to the receiver or transmitter site and providing at that site a decoder suitable for responding to the coded tone to activate a motor which in turn positions the tap of a tuning potentiometer.
Such motorized potentiometers have proven undesirable in many applications since they are expensive, and bulky.